Set-screw.



A. LEVEDAHL.

SET SCREW.

APPLICATION FILED APR. 19, 1909.

Patented 1090.7, 1909.

pniirsn AXEL LEVEDAHL, OIE' AURORA, ILLINOIS,

PATENT oirrrcn ASSIGNOR TO AURORA AUTOMATIC MA- $ET-SCREW.

Specification of Letters Patent.

Patented Dec. *7, 1909.

Application filed April 19, 1909. Serial No. 490,691.

To all whom it may concem:

Be it known that I, Axnn LEV'JDAHL, a citizen of the United States, anda resident of Aurora, in the county of Kane and State of lllinois, haveinvented certain new and usetul linprovenients' in Set-Screws; and I dohereby declare that the following is a full, clear, and exactdescription thereot, reference being had to the accompanying drawings,and to the numerals of reference marked thereon, which form a part ofthis specification.

This invention relates to means for looking or holding set-screws fromrotation, more particularly intended for use in connection withset-screws inserted in parts which are I subject to great jar andvibration such, for instance, as the piston of an internal combustionengine.

The invention consists in the matters hereinafter set forth and moreparticularly pointed out in the appended claims.

In the drawings :--Figure 1 is a view, partially inelevation andpartially in section, oi a piston head, illustrating my inventionapplied thereto. Fig. 2 is acrosssectional view taken upon line 2-2of 1. Fig. 3 is a view in side elevation of the set-screw shown in Figs.1 and 2. Fig. 4- is a view of the set-screw in a different position.Fig. 5 is crosssectional view of the set-screw, taken upon line 5-5 ofFig. 3.

. In the said drawings, designates a hollow piston, of common form,which is pro vided within the same with a tran: rsely extendingpivot-rod (5 by means (it which the pitinan is secured to the pistonhead. The said pivot-rod (S has its ends inserted in transverse sockets7, 7 extending through two oppositely located projections 8, S which areformed upon the opposite parts ot the l cylindric Wall of the. saidpiston and extend inwardly therefrom. The said pivot- I rod (3 isadapted to be secured at its ends in l the sockets 7, 7 and for thispurpose the ends of the said pivot-rod which rest in the said socketsare split or provided with longitudinally extending slots 10, 10 whichpermit the ends of the said pivot-rod to be spread or expanded.Extending transversely of the pivot-rod, with theirlongitudinal axes inthe planes of said slots, are holes or pr i sages 12, 12 which aretapered from end to end. The said tapered holes 12, are adapted toreceive correspondingly tapered l pins pr wedges 13, 13 which, whenforced therein, act to expand or press outwardly the portions of thepivot-rod on each side of the slots 10, 10. The forcing out or expandingot the said parts presses them tightly against the walls of the sockets7, 7 and serves to secure the pivot-rod 6 firmly in place. The said pinsare inserted into the holes 12, 12 through apertures 15, 15 which extendthrough the portions of the projections 8, 8 exterior to the passages 7,7 and in line with the said holes 12, 12 in the pivot-rod The apertures15, 15 are screwthreaded and are adapted to receive set screws 16, 16which hear at their inner ends against the larger ends of the wedges 13,13 and by means of which the said wedges 13, 13 are forced into theholes 12, 1.2 to expand the ends of the pivot-rod (5.

To provide for locking or holding the setscrews from turning backwardlyafter they have been inserted and tightened against the part to besecured or held in place there by, a construction is provided asfollows: The set screws .16, 16 are screw-threaded throughout thegreater portion of their lengths. Each of said set-screws is provided atits outer end with two lateral locking faces 20, 20, shown as made bycutting away the metal at opposite sides of the screw so as to form twoflat faces. The said locking faces 20, 20 are of such length that theinner ends thereof extend inwardly beyond the outer end of thescrow-threzuled aperture 15 when the. set-screw is in place. Thesetscrew, thus provided. with fiat faces 20, 20 extending into thescrew-threzulcd aperture which receives said sctscrew, is held fromturning after the set-screw has been screwed into place by upsetting orswaging the metal at the sides of the aperture 15 so as to bring thesame into contact with the said fiat faces 20, 20, thereby locking theset-screw from rotation. in other words, theswaging of the metal at thesides of the aperture forms inwardly extending projections 25, whichbear against the flat faces 20, 20 and serve to lock the said set-screwagainst turning under the jarring produced by the rapid movements of thepiston. The partial screw-threads remaining upon the portion of theset-screw between the {lat faces 20, 20 act to cut away the projections25, 25 when the set-screw is turned backwardly by a wrench to remove thesame.

1ng face or faces in a screw from backward rotation or becoming Theinner'ends of the sets crew may be provided with reduced cylindricportions 26, 26 adapted to enter each of the apertures 1n the pin 6 whenthe set-screws are used in connection with wedges 13, 13, as-shown. Theouter ends of said set-screws are shown as provided with flattened heads27, 27 to which a wrench may be applied for inserting and removing thesaid set-screws.

It is to be understood that the details of construction illustrated inthe accompanying drawings may be considerably varied without departingfrom the spirit of the invention and I do not wish to be confined tosuch details except as they are hereinafter made the subject of specificclaims. As, for ll'lSll-Zl l1CG,'tl1B set-screw may have only onelooking face, or may have its outer end cut away laterally in any manneror in any form adapted to make the same non-cylindric, or to provide alocking face or faces which may be engaged by an integral part of themetal at the outer end of the hole in which the set-screw is inserted,which is, by a swaging operation, extended partially across the hole andbears against the lockmanner to hold the loosened. v

I claim as my invention l.- The combination witha metal part providedwith a screw-threaded hole, 'of a setscrew which is inserted in saidscrew-threaded hole; said set-screw being provided with a longitudinallyy and which extending, lateral, locking eaaeoe surface on the-portion ofits screw-threadeo lengt. which is located within the outer end of thescrew-threaded hole, and the metal of set-screw which is inserted insaid screwthreaded hole, said set-screw being provided with twooppositely located flat faces which extend along said screw for aportion of the screw-threaded length thereof, and the inner ends ofwhich extend into the screwthreaded hole, said part in which thesetscrew is inserted being provided with inwardly extending projectionswhich are formed by swaging inwardly the metal at the outer end of thescrew-threaded hole engage the fiat faces of the setscrew between theends of the screw-threaded portion thereof to lock the latter againstrotation.

In testimony that I claim the foregoing as my invention I affixmy"signature in the presence of two witnesses, this 16 day of April A.D. 1909. AXEL LEVEDAHL.

Witnesses:

CHAS. H. GREENE, R. A. VORLING.

